Crew seating arrangement

Flight

Launch from Cape Canaveral (KSC);
landing in Cape Canaveral (KSC). The launch of Discovery on
STS-51D was delayed by 55 minutes when a boat strayed
into the restricted
SRB recovery zone.

Mission
STS-51D was originally set for a March launch and
included deployment of the Hughes LEASAT 3 spacecraft and retrieval of
NASA's Long Duration Exposure Facility. It was
remanifested following the decision to cancel Mission
STS-51E, which
was to have been flown by orbiter Challenger. The revised
STS-51D cargo included the Hughes satellite plus the
Canadian communications spacecraft Anik C-1. Other payloads included the
Continuous Flow Electrophoresis System, the American Echocardiograph
Experiment, two middeck student experiments and two Getaway Special canisters.
Also scheduled to fly were a variety of simple toys intended to demonstrate
the unique properties of space flight for elementary and junior high school
students.

Anik C-1 was owned and operated by Telesat Canada, Ottawa.
Anik C-1 was the last of Telesat's trio of 14/12 GHz Anik C satellites. Anik
C-1 was the first satellite placed in final orbit using Telesat's new global
tracking antenna system.Anik C communications satellites were identical,
cylindrical, spin-stabilized spacecraft that operate exclusively in the high
frequency (14 and 12 GHz) satellite radio bands, with 16 transponders
(communications repeaters) each.Each of these 16 satellite channels was
capable of carrying two color TV signals, together with their associated audio
and cue and control circuits, for a total TV signal capacity of 32 programs per
satellite. Anik C-3 and Anik C-2 were carrying Canadian pay television service,
educational broadcasting and long distance telephone and data traffic.Upon
launch from the orbiter by springs, the 2,557-lb. satellite began spinning at
about 50 rpm for stability. About 45 minutes later, or one-half Earth orbit,
its
PAM-D boost motor was ignited by an onboard timer,
kicking the satellite into an approximately 190-by-23,000-mi. elliptical orbit.
At a selected high point in that orbit, another, smaller rocket motor inside
the satellite was fired by ground controllers to increase the satellite's speed
and circularize the orbit at geosynchronous altitude of roughly 22,300
mi.

LEASAT 3, also known as Syncom IV-3, was the third of
four satellites which will be leased by the Department of Defense to replace
older FleetSatCom spacecraft for worldwide UHF communications between ships,
planes and fixed facilities. A Hughes HS-381 design, LEASAT spacecraft are
designed expressly for launch from the Space Shuttle and use the unique
"Frisbee" or rollout method of deployment. The first two spacecraft were
deployed during the STS-41D and
STS-51A Shuttle missions.Interface
between the spacecraft and the payload bay was accomplished with a cradle
structure. The cradle permited the spacecraft to be installed lying on its
side, with its retracted antennas pointing toward the nose of the orbiter and
its propulsion system pointing toward the back. Mounting the antennas on
deployable structures allowed them to be stowed for launch.Five trunnions
(four longeron and one keel) were used to attach the cradle to the Shuttle.
Five similarly located internal attach points were used to attach the
spacecraft to the cradle.Another unique feature of the LEASAT series of
satellites was no requirement for a separately purchased upper stage, as have
all the other communications satellites launched to date from the
Shuttle.The LEASAT satellites contained their own unique upper stage to
transfer them from the Shuttle deploy orbit of about 182 mi. to a circular
orbit 22,300 mi. over the equator.Each satellite was 20 ft. long with UHF
and omni-directional antennas deployed. Total payload weight in the Shuttle was
17,000 lb. The satellite's weight on station at the beginning of its planned
7-year life was nearly 7,900 lb. Hughes Space and Communications Group builded
the satellites.Ejection of the spacecraft from the Shuttle was initiated
when locking pins at the four contact points are retracted. An explosive device
then releases a spring that ejects the space craft in a "Frisbee" motion. This
gave the satellite its separation velocity and gyroscopic stability. The
LEASAT-3 spacecraft sequencer failed and the OMNI antenna was not deployed and
the perigee kick motor did not start. The mission was extended two days to make
certain the sequencer start lever was in the proper position for deployment of
the OMNI antenna. Jeffrey
Hoffman and David
Griggs performed a not planned spacewalk on April 16,
1985 (3h 08m) to attach Flyswatter devices to remote manipulator system. Rhea
Seddon engaged LEASAT lever using the remote manipulator
system but the post deployment sequence did not begin.

The middeck
Continuous Flow Electrophoresis System (CFES) unit made its sixth spaceflight on mission
STS-51D. Payload specialist Charles
Walker, of McDonnell Douglas, operated the system. This was
the second Space Shuttle flight for Charles
Walker as a payload specialist.The primary objectives of
the flight were to separate and collect a quantity of protein material and to
evaluate contamination control and sample stream dynamics.During the
STS-41D mission in August/September
1984, the middeck
CFES unit separated 83 percent of the concentrated
protein material on board. However, post flight assays revealed levels of
endotoxin contamination which rendered the hormone unsuitable for animal
testing. To prevent a recurrence, stronger sterilizing chemicals will be used
preflight to cleanse the middeck unit. Also, procedures have been modified to
maintain cooler operating temperatures throughout the course of the mission in
an effort to retard bacterial growth. Additionally, the degassing units and
sensors which failed during the STS-41D
were replaced. Software modifications were made to the system's computer
control device to lengthen the unit's response time between commands.
Difficulties in the automation software were causing the system to adjust too
quickly. Once each day Charles
Walker tested for the presence of microbes and endotoxins.
These tests were made by withdrawing a small sample of fluid from five
locations and incubating them in vials which have been loaded previously with
freeze-dried reactants.

Protein Crystal Growth Experiment:
Detailed knowledge of the composition and structure of proteins is extremely
important to the understanding of their nature, chemistry and the ability to
manufacture them for medical purposes. However, for most complex proteins, it
has not been possible to grow, on Earth, crystals large enough to permit X-ray
or neutron diffraction analyses to obtain this information.A device has
been developed by Marshall Space Flight Center, Huntsville, Ala., that should
enable the growth of such crystals in the weightlessness of orbital spaceflight
where gravity-driven convection currents are minimized, and where the crystals
do not sediment but remain suspended while they develop optimum size and
conformation.The first exploratory flight of such equipment involved the
use of a small device that fit within a part of a standard middeck locker.
McDonnell Douglas Astronautics had agreed to include this unit in one of the
middeck lockers used in conjunction with the flight of the
CFES experiment on this flight. The
CFES payload specialist, Charles
Walker, was trained in the preparation of the unit.A key
objective of the overall protein crystal growth program was to enable drug
design without the present empirical approach to enzyme engineering and the
manufacture of chometherapeutic agents.

Two Space Shuttle Student
Involvement Program experiments flew aboard Shuttle mission
STS-51D.One experiment, proposed by Sean Amberg of
Seward, NE., was titled "Statoliths in Corn Root Caps". This experiment looked
at the effect of weightlessness on the formation of statoliths (gravity sensing
organs) in plants, and was tested by exposing plants with capped and uncapped
roots to space flight. The root caps of the flight and control plants were
examined post-flight by an electron microscope for statolith changes.The
second student experiment was "The Effect of Weightlessness on the Aging of
Brain Cells", proposed by Andrew Fras of Binghamton, NY. This experiment (using
houseflies) was expected to show accelerated aging in their brain cells, based
on an increased accumulation of age pigment in, and deterioration of, the
neurons.

American Flight Echocardiograph (AFE): Understanding the
effects of weightlessness on the cardiovascular system of astronauts is
important for both personal and operational safety reasons. The dynamics of the
heart pump action is one possible factor in the adaptation of the
cardiovascular system to weightlessness.The newly available American Flight
Echocardiograph (AFE) instrument was used to acquire in-flight data on these
effects during the course of space adaptation for the purpose of developing
optimal counter measures to crew cardiovascular changes (particularly during
reentry) and to ensure long-term safety to people living in
weightlessness.The AFE weighed about 43 lb. and was carried within a
standard locker from which it will be operated. One crewmember was trained in
the technique of obtaining clinical grade self-administered
echocardiograms.

The first exploratory flight of Phase Partitioning
Experiment (PPE) equipment involved the use of a small, handheld device, a
little larger than a cigarette box and weighing about 1 pound. This unit will
fit within a small part of a standard middeck locker. On flight
STS-51D, it was planned that payload specialist Jake
Garn
should conduct this experiment in addition to some investigations in the space
adaptation syndrome. The unit had 15 chambers to allow the test of different
volume ratios and compositions of the phases and differences in wall coatings
with in the chambers.Phase partitioning is a selective, yet gentle and
inexpensive technique, ideal for the separation of biomedical materials such as
cells and proteins. It involves establishing a two-phase system by adding
various polymers to a water solution containing the materials to be separated.
Two phase systems most familiar to us are oil and water or cream and milk. When
two phase polymer systems are established, the biomedical material they contain
tend to separate or "partition" into the different phases.

Jake
Garn, a
U.S. Senator from Utah, was the first public official to fly aboard the Space
Shuttle. Jake
Garn
was onboard as a payload specialist and Congressional observer. As payload
specialist, he carried out medical physiological tests and measurements. Tests
on Jake Garn seeked to detect and record changes the body undergoes
in weightlessness, an ongoing program that began with astronauts on the fourth
Shuttle flight. The first, during launch, was Jake
Garn
wearing a waist belt with two stethoscope microphones fastened to an elastic
bandage. At main engine cutoff, about 8 ½ minutes into the flight, the
belt was plugged into a portable tape recorder stored in the seat flight bag
and begins recording bowel sounds to evaluate early inflight changes in gastric
mobility. A non-medical activity planned for Jake
Garn
was the Phase Partitioning Experiment (PPE) in which fluid mixtures of
different densities are photographed to analyze the characteristics of their
separation during weightlessness.

The
STS-51D crew demonstrated the behavior of simple toys
in a weightless environment. The results, recorded and video taped, became part
of a curriculum package for elementary and junior high students through the
Houston Museum of Natural Science.Studies have shown that students can
learn physics concepts by watching mechanical systems in action. In an
Earth-based classroom, the gravitational field has a constant value of 1-g.
Although the gravity force varies greatly throughout the universe and in
non-inertial reference frames, students can only experiment in a constant 1-g
environment. The filming of simple generic- motion toys in the zero-g
environment of the Space Shuttle will enable students of all ages to share a
learning experience and discover how the different toy mechanical systems work
without gravity.The following members of the
STS-51D crew demonstrated the effects of
weightlessness on "dime-store" toys:Karol
Bobko
- a spinning top and three unrestrained gyroscopesDonald
Williams - a spring-wound flipping mouse and a paddle ball.
He will also tried to perform a juggling act in zero-gRhea
Seddon - a ball and jacks and a SlinkyDavid
Griggs - a yo-yoJeffrey
Hoffman - a Wheelo, magnetic marbles and a
spring-wound.

An experiment to test low light level photographic
equipment, in preparation for next year's visit by Halley's Comet, was planned.
Mission specialist Jeffrey
Hoffman, an astronomer and astrophysicist, checked out an
image intensifier coupled with a Nikon camera, a combination that intensifies
usable light by a factor of about 10,000.

During the shuttle's landing
at KSC on
April 19, 1985, extensive brake damage was suffered, and a landing gear tire
ruptured. This prompted future shuttle flights to land at Edwards Air Force
Base, California, until effective nose wheel steering could be implemented to
reduce risks during landing.